(a) Field of the Invention
The present invention relates to a golf club head, especially relates to so-called an iron golf club head or a putter golf club head.
(b) Description of Prior Art
It is mainly for the purpose of enlarging so-called a sweet area and lowering the center of gravity of a golf club head that the weight distribution of a golf club head including an iron golf club head or the like is adjusted in an invention concerning a golf club head. It is obvious to those skilled in the art that to enlarge a sweet area, the center of gravity of a club head should be positioned comparatively backward, or else, the weight distribution of a golf club head should be concentrated upon a peripheral portion relative to a face besides the enlargement of a bulk of a golf club head itself. One of the representative of a means for realizing such weight distribution is disclosed in U.S. Pat. No. 3,847,399, in which a head body is formed hollow, or a back surface of a club head is formed with a cavity. On the other hand, it is mainly for the purpose of making a golf ball fly more upwardly and travel a longer distance to lower the center of gravity of a club head.
However, especially for an iron club head, it is difficult to make the same hollow. Further, only a cavity formed in a back surface of a club head made of a single material cannot sufficiently concentrate the weight distribution of a club head upon a peripheral portion, thus having a limitation in enlarging a sweet area.